Top panel: Average interval between the deep trapped modes during the second stage of evolving the sdB models for the CPM scheme, as shown in Fig. 4b by red dots, and the observed mean distances between three deep trapped modes of KIC 10001893, depicted with a blue line. Middle panel: Mean period spacing without considering the deep trapped modes in the first and second evolutionary stages of the sdB models, illustrated by red dots. The blue line represents the observed mean period spacing, excluding three deep trapped modes and three semi-trapped modes of KIC 10001893. Bottom panel: Mean period spacing of all modes in all the evolutionary stages of He-burning of the sdB models, as depicted by red dots. The blue line displays the observed mean period spacing of all modes of KIC 10001893.